.poster-content-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 10px;
    height: 100%;
    width: 100%;
    box-sizing: border-box;
}

button {
    margin-top: 25px;
    width: 150px;
    height: 30px;
    line-height: 30px;
}